Moderate consumption of alcohol may reduce the risk of suffering one type of stroke while heavy drinking may greatly increase the chances of suffering another kind, cardiologists at the Kaiser Permanente Medical Center in Oakland reported last week in the journal Stroke.

A year and a half after its approval, surveys show many doctors are still afraid to use a clot buster as the first emergency treatment for strokes because of the potential dangers. The slow acceptance of tissue plasminogen activator (TPA) was one of the primary topics of discussion at the American Heart Assn.'s 23rd International Joint Conference on Stroke and Cerebral Circulation, which was held in Orlando. The Food and Drug Administration approved TPA in June 1996.

Neuroscientists report they have developed the first effective emergency therapy for stroke, an advance that could prevent as many as 44,000 Americans a year from becoming disabled. The treatment involves intravenous injection of the clot-dissolving enzyme t-PA--the same enzyme used to treat clots in the heart--into patients within three hours after the onset of stroke symptoms.

Mayor Edward I. Koch has suffered a small stroke but is expected to recover fully, his physicians said Friday after conducting a series of specialized tests. Koch, 62, who had been hospitalized Thursday after complaining of dizziness and nausea, was transferred by ambulance to the Neurological Institute of Columbia-Presbyterian Medical Center early Friday after his symptoms recurred. Prognosis Is Excellent Dr. J. P.

Stroke victims are often left incapacitated, unable to speak clearly, walk without assistance or do routine tasks such as grooming and feeding themselves. Because current physical therapy can go only so far in restoring lost abilities, many of them must learn to accept their new limitations. An experimental device may eventually be able to help such patients resume relatively normal lives.

Coretta Scott King suffered a minor heart attack and a major stroke that impaired her ability to speak and affected her right side, but she is "completely aware," a doctor said in Atlanta. Dr. Charles Wickliffe, a cardiologist at Piedmont Hospital, where the 78-year-old widow of civil rights leader the Rev. Martin Luther King Jr. had been hospitalized for two days, said a blood clot had moved from King's heart and lodged in an artery in the left side of her brain.

Australian tennis legend Rod Laver, who suffered a moderate stroke July 27, was released from UCLA Medical Center on Thursday. Laver, wearing a UCLA tennis cap, tossed a tennis ball with his right hand from his wheelchair to one of his doctors, Eric Aldrich. Aldrich also threw a tennis ball to Laver, who caught it with his right hand.

Former President Gerald R. Ford stepped off a private jet at Palm Springs Airport on Wednesday afternoon and got into a car for a brief drive to his Rancho Mirage home more than a week after suffering a stroke in Philadelphia. Ford, arriving with his wife, Betty, and daughter, Susan, waved to a small crowd before leaving the airport by private car. Doctors at the Philadelphia hospital where Ford was treated said the 87-year-old former president is in excellent health and his prognosis is good.

Sen. John McCain's wife was moved out of an intensive care unit, two days after she had a stroke, and was expected to be released from a Phoenix hospital in a few days. Cindy McCain, 49, suffered minor bleeding in her brain when a blood vessel ruptured Monday, possibly because of a spike in blood pressure, said Robert Spetzler, director of the Barrow Neurological Institute at St. Joseph's Hospital.

Lt. Gov. Joe Kernan assumed the duties of acting governor as Gov. Frank O'Bannon lay in critical condition after a stroke. Doctors said that O'Bannon, 73, had evidence of brain damage and that it was too soon to say whether he would recover. They said he would probably stay in an induced coma for several days. O'Bannon, a Democrat in his second term, was found unconscious and near death on the floor of his Chicago hotel room Monday morning.